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Amber

Last updated: April 2026

Fossilized tree resin; low density and organic inclusions distinguish it from glass and copal. Baltic amber fluoresces strong blue to bluish-white under LW UV. Dominican and Mexican amber show vivid sky-blue LW fluorescence. Burmese (Burmite) amber tends toward green or yellow fluorescence.

Amber has a specific gravity of 1.08 and a refractive index of 1.539–1.545, with a Mohs hardness of 2.0–2.5. It is singly refractive.

Physical & Optical Properties

RI Range1.539–1.545
SG Range1.05–1.09
SG Typical1.08
Hardness (Mohs)2–2.5
Crystal SystemAmorphous
Optic CharacterSR (Singly Refractive)
Dispersion0.000
Fluorescence LWStrong blue
Fluorescence SWModerate Blue White
Chelsea FilterInert
PleochroismNone
ColorsYellow Orange, Brown, Red Pink, Green, Blue Violet
SpeciesOrganic
Yellow OrangeBrownRed PinkGreenBlue Violet

Measured with a polariscope, a refractometer, a hydrostatic balance, a Chelsea filter, a UV torch, a loupe, a darkfield loupe and a spectroscope — step-by-step for each.

Through the refractometer

Amber reads 1.542 1.40 1.45 1.50 1.55 1.60 1.65 1.70 1.75 1.80 REFRACTIVE INDEX DORotate the stone through a full 360°, watching the boundary. SEEOne boundary, at 1.542, and it does not move as you rotate. MEANSSingly refractive. A stationary single edge through thewhole rotation is the observation that says so. Computed from gems.json — edge positions are arithmetic, not drawn. RI increases upward; the field above the boundary is the dark one.

Drawn from the refractive index above, on a 1.40–1.81 scale. How to take this reading.

CoralIvoryPearl

Key Differentiators

Treatments

Measurement Guides

How to Identify a GemstoneHow to Measure Specific GravityHow to Use a RefractometerUV Fluorescence Testing

Identifying an amber? Loupewise walks through these tests in order — RI, SG, fluorescence, and more.

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Studying for the GIA, FGA, or FEEG practical? Amber is one of the 132 species in Loupewise’s drill and exam pool — practice identifying it from its measured properties under timed exam conditions.

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